[0001] The present invention relates to a refrigerator comprising a refrigerating compartment,
a vegetable storage drawer slidably mounted on a bottom wall of the refrigerating
compartment and an absorbing member disposed in said compartment.
[0002] A refrigerator of this kind is disclosed by
US5253488 where the absorbing member is a gas absorbing member mounted above the vegetable
storage drawer and used for absorbing a noxious gas, particularly ethylene, generated
from the vegetables.
[0003] Usually in the vegetable storage drawer, known also as "crisper drawer", there is
quite a huge amount of humidity that is generated by food and it can lead to an increase
of microbial growth and in some case to a presence of molds on food surface or rotten
food items. These phenomena cause the food waste at consumer level.
[0004] Usually, in order to reduce the amount of humidity in the crisper drawer, a fan is
used to increase the air circulation but this solution implies a high energy consumption.
[0005] The problem of condensation of humidity in the area of the crisper drawer is even
exacerbated in built-in "bottom mount" products where a freezer compartment is placed
below a refrigeration compartment. The applicant has discovered evidences of internal
condensation issue under the shelf, above the crisper drawer and below the drawer,
in a portion of the refrigerator cavity inner liner which is designed in such a way
to increase its overall capacity but that actually reduces the insulation properties
of the insulated wall (mullion) between the freezer cavity and the refrigeration cavity.
[0006] In figures 1 and 2 it is shown a built-in refrigerator according to prior art, where
RC indicates the refrigerator cavity (with temperatures usually ranging from 1°C to
5°C) and FC indicates the freezer cavity (with temperatures ranging from -20°C to
-18°C). In figure 2 it is shown the zones where applicant has discovered major condensation
issues.
[0007] The above issues have been discovered by using an internal test procedure carried
out on bottom mount built-in commercial refrigerator Whirlpool CB310 Revo, where the
objective was to assess the presence of internal condensation under crisper shelf
in the refrigerating cavity RC. According to the applicant's internal procedure, the
test is considered successful if there are no drops of condensation under the crisper
shelf during a five days period with a wet leafy vegetables load placed inside the
drawer.
[0008] After the tests, water drops formation was observed on the bottom part of the liner
as well as fog and condensation dripping under the crisper glass, especially on the
rear surface.
[0009] Condensation issue is much more evident in built-in products rather than free standing
products because of the configuration of the mullion and the reduced foam wall thicknesses.
Moreover, because of the temperature difference between the top surface of freezer
cavity FC and bottom of the refrigerating cavity RC, condensation issue occurs mainly
on the bottom side of refrigerating cavity RC due to water drops falling / accumulation,
or to a temperature distribution between the surface of the mullion close to the air
temperature dew point.
[0010] An object of the present invention is to provide a refrigerator of the type mentioned
at the beginning of the description in which the above water condensation issues are
solved in an effective and economical way.
[0011] The above object is reached tanks to the features listed in the attached claims.
[0012] According to the invention, the applicant has discovered a simple way to absorb the
water drops on the bottom surface of the refrigerating compartment RC by using a tray
in which it is placed and absorbing material, preferably a zeolite powder.
[0013] Zeolite powder is able to absorb water drops as well as fog and humidity so that
condensation tests can be passed without changing the liner shape (which could lead
to a decrease of overall capacity of the storage cavity) or the crisper shelf position
and configuration.
[0014] In order to avoid a decrease of the refrigeration capacity, to keep the same liner
shape and to avoid a change of the crisper shelf position, according to a first embodiment
of the invention the humidity is absorbed by using a zeolite tray, positioned under
the crisper drawer, which is designed with a grid on the bottom surface, so that water
drops can be collected by the lower tray. Being placed below the crisper drawer and
not above it, the zeolite powder is able to collect the humidity of the whole refrigerating
compartment RC, acting like a sponge.
[0015] Therefore, according to the invention, the tray below the crisper has actually two
main functions, i.e. to collect the water drops coming from the crisper and to collect
the humidity that occurs because of the low foam wall thickness between the refrigerating
compartment RC and the freezer compartment FC (mullion).
[0016] The water drops that usually occur into the crisper and under the shelf above it
are expected to fall down and drip through to the grid into the zeolite powder.
[0017] The zeolite powder is preferably not directly accessible: it is preferably positioned
in a small tray placed under the crisper, onto the bottom surface of the RC liner.
The zeolite tray is made by two components: the slab made of molded zeolite powder
and a cover with grid, through which the water drops coming from the above crisper
and fog are expected to pass through.
[0018] Further advantages and features of a refrigerator according to the present invention
will be clear from the following detailed description, provided as non limiting examples,
with reference to the attached drawings in which:
- Figures 1 and 2 are section views of a built-in refrigerator according to prior art;
- Figure 3 is a section view of a refrigerator according to the invention;
- Figure 4 is a perspective sectioned view of the refrigerator of figure 3;
- Figure 5 is an enlarged view of a detail of figure 3; and
- Figures 6-7 are perspective views of a component used in the refrigerator of figures
3-5, in an exploded and mounted configurations respectively.
[0019] With reference to the drawings, a built-in refrigerator 10 comprises a top fresh
food compartment RC and a bottom freezer compartment FC which are separated one from
the other by a mullion 12. On a bottom surface 12a of the compartment RC, a crisper
drawer 14 is slidably mounted. Such drawer is sliding on guide rails 15 provided on
the side walls of the liner, so that an inner space S is defined between the drawer
outer walls and the liner in order to increase the air flow around the crisper drawer
14.
[0020] In such space S and on the bottom wall 12a of the compartment, a tray 16 is placed
which is formed by a plate or slab 16a of molded zeolite powder, sandwiched between
a bottom plastic support 16b and a top plastic grid 16c which covers the plate 16a
of zeolite.
[0021] The crisper drawer 14 is provided, on its bottom wall 14a, with a plurality of apertures
18 defining a further grid which faces the grid 16c of the tray 16. In this way the
plate 16a of the tray 16 is not only able to absorb humidity and/or other noxious
gases, but it allows the condensed water in the crisp drawer 14 to drip in the tray
16 and to be absorbed by the zeolite material. In order to allow absorption of any
water resting on the bottom surface 12a of the compartment RC, the bottom plastic
support 16b of the tray 16 is provided with apertures 20.
[0022] In another embodiment of the invention, the tray 16 may be placed directly inside
the drawer 14, for instance as an auxiliary small drawer sliding inside the crisper
drawer 14.
[0023] Independently on the actual position of the tray 16 within the refrigerating compartment
RC, the zeolite material contained therein can be easily regenerated by placing the
entire tray 16 in an oven at a temperature around 100°C for few minutes. The same
regeneration process may happen by simply taking out the tray 16 from the refrigerator
and leave it in a room whose air has a usual humidity content (up to 50% relative
humidity).
[0024] The technical solution hereby disclosed allows applying a sort of calcareous stone
self-regenerating as filters to absorb relative humidity inside the crisper drawer
for fruits and vegetables. The proposed solution is made by a removable tray in which
there is the zeolite molded podwer presenting as a stone. The tray is placed in the
bottom part of RC compartment and presents a grid facing a corresponding grid provided
on the bottom wall of the drawer to hold and support all the vegetables inside the
drawer, keeping them separated by the zeolite. The humidity level is reduced by zeolite
that absorbs the water drop/condensation and moisture through both grids. It is not
necessary to remove the water from the tray 16 because the stone absorb it and it
self-regenerates. Zeolites are widely used as ion-exchange beds in domestic and commercial
water purification while in chemistry they are widely used to separate molecules;
they are also widely used as catalysts and sorbents. Their well-defined pore structure
and adjustable acidity make them highly active in a large variety of reactions. Zeolites
have the potential of providing separation of gases including the removal of H2O,
CO2 and SO2 from low-grade natural gas streams. The solution according to the invention
provides several benefits to user: no bacterial contamination coming from high humidity
environmental on fruits and vegetables surface and so reduce food waste; no formation
of drops of water inside crisper bin during vegetables storage; no needed use of fans
or similar devices to reduce the condense and therefore reduced energy consumption;
zeolites do not need to be replaced due to natural capability to regenerate; zeolites
permit to reduce the cleaning activities at consumer level; zeolites are not in direct
contact with food; zeolites have a wide range to work both in terms of temperature
and relative humidity; zeolites can be also used as effective odor absorber.
1. Refrigerator (10) comprising a refrigerating compartment (RC), a vegetable storage
drawer (14) slidably mounted on a bottom wall (12a) of the refrigerating compartment
(RC) and an absorbing member disposed in said compartment, characterized in that such absorbing member (16) is placed below said drawer (14) so that it can absorb
water dripping from such drawer (14) and/or condensing on said bottom wall (12a).
2. Refrigerator according to claim 1, wherein the vegetable storage drawer (14) is provided
with a plurality of apertures (18) on its bottom wall (14a).
3. Refrigerator according to claim 1 or 2, wherein the absorbing member (16) is a plate
(16a) molded from a zeolite powder placed on the bottom wall (12a) of the refrigerating
compartment (RC).
4. Refrigerator according to claim 3, wherein the plate (16a) of the absorbing member
(16a) is contained in a tray (16) removably disposed on the bottom wall (12a) of the
refrigerating compartment (RC).
5. Refrigerator according to claim 1, wherein the absorbing member is a plate molded
from a zeolite powder placed on a bottom wall (14a) of the drawer (14) and on which
a grid or the like is present.
6. Refrigerator according to any of the preceding claims, wherein the refrigerating compartment
(RC) is placed above a freezing compartment (FC) and separated therefrom by an insulated
mullion (12).